Spare a thought, if you can, for cabinet ministers' special advisers. The title is sonorous enough though its abbreviation into "spad" sounds like an unappetising cooked meat. Spads operate in that bumpy terrain extending between civil service officialdom where public business is minuted to within an inch of its life, and the more private domain of the ministerial circle where information is assessed, gossip exchanged, and decisions made. Spads are ministers' personal appointees, and they are therefore courtiers who must please their patrons. But they are bound by the civil service's risk-averse codes of conduct. A spad's position is often happy but the role's ambiguities can make for a rough ride.

Spads have few friends. Permanent civil servants know that special advisers are here today but may be gone quite soon. MPs view them with suspicion: cocky spads will happily drop hints about what they've read in cabinet documents in order to make parliamentarians feel more than usually excluded. Spads make few House of Commons appearances. Many may wish to be fast-tracked into a seat, but that acquisition is just a tedious detour before, they hope, the moment arrives when they can have their own spads to play with.

It's a standard hypocrisy of our public life that all parties, when in power, need spads, and that all parties, when in opposition, excoriate them. Contemporary spadocracy starts with Jack Straw, who was Barbara Castle's special adviser at Social Security from 1974 to 1976. But there were plenty of proto-spads. Lloyd George brought Thomas Jones in from university life in 1916 to be the cabinet's deputy secretary, Winston Churchill made Frederick Lindemann – "The Prof" – his special scientific adviser in 1940, and Ted Heath appointed the zoologist Victor Rothschild to be head of his Central Policy Review Staff in 1971. All three premiers were unusually strong-minded executives who were impatient with the self-protective neutrality of the civil service – an empire with a habit of hitting back discreetly. Gordon Brown's prime ministerial pledge to reduce Whitehall civil servant numbers was abandoned almost as soon as it was made.

Spads you may like or not. But they will always be around. British government remains cumbersome, rather gentlemanly and amateurish in its conventions, and resistant to the policy initiative. Spads exist to liven it up – and they will often get into trouble since it's practically impossible to separate the political from the purely administrative. There are now more than 35 years' worth of post-Straw advisers. Some have blazed trails. The policy-enriched brothers Miliband were the uber-spads of their epoch. David Cameron did wonders in cooling down Michael Howard at the Home Office. Alastair Campbell was technically a spad although his ways with dossiers made life difficult for the breed as a whole. Spads should cast light on governmental obscurity and avoid personal publicity if at all possible. But when dragged blinking into the light of an accusatory day they should co-operate with Sir Humphrey. That's what I did when I was a spad at the Welsh Office, and Dominic Cummings will be doing the same. He should also remember that spads are the Gloria Gaynors of British politics; they tend – one way or another – to survive.